In late 1944, during an American bombing raid over Germany, a B-17 was heavily damaged and crash-landed in a heavily forested area. The remaining crew survived the landing and were able to steal a German radio from a farm they crashed next to, and using that radio called for help. A team of Allied paratroopers were dropped into the area to find the American bomber crew. Naturally, all this activity made the German units nearby curious, so they moved in on the crash site.
